Flux 2 Klein 9B Edit

bfl/flux-2/klein/9b/edit

Flux 2 Klein 9b by BFL - AI-powered image editing, style transfer, and transformation. Edit photos with natural language instructions, remove backgrounds, change styles, and enhance images effortlessly.

Base price
$0.02USD / run
Execution
async
Model type
image
Input fields
6
Production route

Try the model

Playground

Open playground
Input
The prompt to edit the image.

PNG, JPEG, WebP, or GIF · 20 MiB maximum each

The URLs of the images for editing. A maximum of 4 images are allowed.
48
The number of inference steps to perform. Range: 4 to 8.
The format of the generated image. Allowed values: jpeg, png.
The aspect ratio of the generated image. Allowed values: 21:9, 16:9, 3:2, 4:3, 5:4, 1:1, 4:5, 3:4, 2:3, 9:16.
The seed to use for the generation. If not provided, a random seed will be used.
OutputReady

Your output will appear here

Complete the inputs, then click Run.

Model card

Specifications

Pricing

Base price
$0.02 / run

Context & modalities

Input
Schema-defined
Output
image

Capabilities

Chat
Not supported
Vision
Not supported
Reasoning
Not supported
Structured output
Not supported
Function calling
Not supported
Audio input
Not supported

Access

Provider
BFL
Model ID
bfl/flux-2/klein/9b/edit
Execution
async
Base URL
https://api.sandbase.ai
API
Unified Run API
Endpoint
/v1/run

Human preference

Arena

Elo ratings from blind side-by-side votes, compared with other image and video models.

Rankings sourced from Artificial Analysis Arena

Leaderboard
Image Editing
Rank
#44 of 77
Elo
1015 ±13
Gap to #1
−184

Image-editing arena: people pick the better of two edits of the same image and instruction, without seeing the model names.

  1. #39Luma UNI 1Luma Labs1043±13
  2. #40Seedream 4.5ByteDance SeedOn SandBase1043±13
  3. #41Wan 2.7AlibabaOn SandBase1042±13
  4. #42HunyuanImage 3.0 (Tencent Cloud)Tencent1029±16
  5. #43FLUX.2 [dev] TurboFalOn SandBase1019±18
  6. #44FLUX.2 [klein] 9BBlack Forest LabsThis model1015±13
  7. #45FLUX.2 [dev] FlashFalOn SandBase1012±18
  8. #46FLUX.2 [pro]Black Forest LabsOn SandBase1012±15
  9. #47Step Image Edit 2StepFun1009±13
  10. #48FLUX.2 [dev]Black Forest LabsOn SandBase1000

API README

Flux 2 Klein 9B Edit

FLUX.2 [klein] 9B, a compact open model for fast, low-cost images. Edit or combine images with an instruction.

Fields

FieldTypeDefaultNotes
promptstring, required—Text instruction.
imagesimage URL[]—Images to edit or combine, Image 1, Image 2, …
num_inference_stepsinteger 4–84More steps add detail and time.
output_formatjpeg / pngpngOutput file format.
aspect_ratio21:9 / 16:9 / 3:2 / 4:3 / 5:4 / 1:1 / 4:5 / 3:4 / 2:3 / 9:16—Output shape.
seedintegerrandomFix it to compare prompt changes.

Billing

$0.022 per image.

RequestPrice
One image$0.022

Failed runs are not charged.

Prompting

  • Say which image is the base and what each other image contributes.
  • List what must not change.

Limits

  • One output image per request.

Also on SandBase

Other FLUX.2 endpoints: bfl/flux-2/max/edit, bfl/flux-2/pro/edit, bfl/flux-2/flex/edit, bfl/flux-2/dev/edit, bfl/flux-2/klein/9b.

Start building

Send your first request

OpenAI-compatible endpoint with unified authentication and usage tracking.

Production API
Unified Run API endpoint
https://api.sandbase.ai/v1/run
Model ID
bfl/flux-2/klein/9b/edit
# The quoted heredoc keeps Unicode and shell metacharacters unchanged.
result=$(curl --fail-with-body --silent \
  -X POST "https://api.sandbase.ai/v1/run" \
  -H "Authorization: Bearer $SANDBASE_API_KEY" \
  -H "Content-Type: application/json" \
  --data-binary @- <<'SANDBASE_JSON'
{
  "model": "bfl/flux-2/klein/9b/edit",
  "images": [
    "https://static.sandbase.ai/examples/bfl/flux-2/klein/9b/edit/input_images_0.png"
  ],
  "prompt": "Turn this into a realistic image",
  "output_format": "png",
  "num_inference_steps": 4
}
SANDBASE_JSON
)
run_id=$(printf '%s' "$result" | jq -r .id)
for attempt in $(seq 1 120); do
  status=$(printf '%s' "$result" | jq -r .status)
  case "$status" in completed|failed|timeout) break ;; esac
  sleep 2
  result=$(curl --fail-with-body --silent \
    -H "Authorization: Bearer $SANDBASE_API_KEY" \
    "https://api.sandbase.ai/v1/run/$run_id")
done
status=$(printf '%s' "$result" | jq -r .status)
[ "$status" = completed ] || { echo "Generation ended: $status" >&2; exit 1; }
printf '%s\n' "$result"

Choose your model

Compare models

All image & video models
ModelTypeDefault priceReleased
BFLImage$0.02 / runJan 15, 2026
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BFLImage$0.05 / runOct 1, 2026
BFLImage$0.02 / runJan 15, 2026
BFLImage$0.01 / runJan 15, 2026
BFLImage$0.01 / runJan 15, 2026

Questions

FAQ

How do I call BFL Flux 2 Klein 9B Edit through SandBase?

Create a SandBase API key, then send requests with the model ID "bfl/flux-2/klein/9b/edit" to Unified Run API (/v1/run) at https://api.sandbase.ai. The request examples on this page show the exact payload.

Do I need a separate BFL account?

No. One SandBase API key and balance gives you access to BFL Flux 2 Klein 9B Edit and the other models in the catalog; you do not need to sign up with BFL separately.